From f194aedbf0a715f8c18b3eca23424e2d2b4dd2b3 Mon Sep 17 00:00:00 2001
From: Jon Chambers <jon.chambers@gmail.com>
Date: Tue, 4 Jun 2019 08:13:44 -0400
Subject: [PATCH] Close delegate resolver from RoundRobinInetAddressResolver
 (#9214)

Motivation:

RoundRobinDnsAddressResolverGroup ultimately opens UDP
ports for DNS resolution. Callers likely expect that
RoundRobinDnsAddressResolverGroup#close() will close those
ports, but that is not currently true (see #9212).

Modifications:

Overrode RoundRobinInetAddressResolver#close() to close
the delegate name resolver, which in turn closes any UDP
ports used for name resolution.

Result:

RoundRobinDnsAddressResolverGroup#close() closes UDP ports
as expected. This fixes #9212.
---
 .../io/netty/resolver/RoundRobinInetAddressResolver.java     | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/resolver/src/main/java/io/netty/resolver/RoundRobinInetAddressResolver.java b/resolver/src/main/java/io/netty/resolver/RoundRobinInetAddressResolver.java
index f505328a39..0a72a730a6 100644
--- a/resolver/src/main/java/io/netty/resolver/RoundRobinInetAddressResolver.java
+++ b/resolver/src/main/java/io/netty/resolver/RoundRobinInetAddressResolver.java
@@ -100,4 +100,9 @@ public class RoundRobinInetAddressResolver extends InetNameResolver {
     private static int randomIndex(int numAddresses) {
         return numAddresses == 1 ? 0 : PlatformDependent.threadLocalRandom().nextInt(numAddresses);
     }
+
+    @Override
+    public void close() {
+        nameResolver.close();
+    }
 }